I love San Antonio. The River Walk is just as beautiful as in the
brochures. One thing that a lot of people miss is the Mission Trail. If
you have at least 1/2 day, this is worth doing. If you like biking, you
could do it on a bike. There are a lot of bike trails in the areas of the
missions. If not interested in a bike, you can do it by public transport,
but a car is better. One of the missions has a Sunday morning mariachi
mass, which is hauntingly beautiful. You'll have to inquire, as I can't
remember which Mission.

There are a couple of B&B's in the King Williams Historic District which
looked very nice (great area) but we didn't stay in them, so no first hand
experience.